Studies on the Behaviour of Adult Australasian Anophelines

Abstract

Observations are recorded on the habits and behaviour of wild adultA. amictus hilliandA. punctulatus farautiat Cairns, North Queensland, and of the two subspecies and intermediate forms ofA. punctulatusin New Guinea.The most important points determined, which bear on the control of adults ofA. punctulatus, are:—(1) Females disperse from the breeding area shortly after emergence. During the day, they are rarely found indoors in any numbers, but hide away in moist, sheltered places in the bush in the vicinity of the source of the blood-meal. Fertilisation of the female takes place here, and these diurnal resting places are vacated only for the purposes of feeding and oviposition.(2) Both before and after feeding, females rest on the walls, etc., of huts and houses, which they readily enter. There is some evidence that the normal flight is dose to the ground, and only comparatively small numbers enter houses built several feet off the ground.(3) Activity does not usually commence until just after dark, and the peak of abundance occurs in the early hours of the morning.(4) Females may disperse at least one mile from their breeding grounds in search of a blood-meal.(5) In New Guinea there is a distinct preference for the native.(6) WhilstA. pundulatus farautidoes not show any marked preference for man, animal or bird,A. pundulatus pundulatushas very definite androphilous tendencies.The habits ofA. amictus hilliare broadly similar to those ofA. pundulatus farauti, but differ in important details. It does not rest indoors during the day, but its favoured outdoor habitat awaits determination. Only a few females were found at Cairns in the bush diurnal resting places used byA. pundulatus farauti, whilst the large numbers observed on the breeding area were there for the purposes of oviposition. Fertilisation takes place in the breeding area, where the males remain. There also appears to be a different nocturnal periodicity from that observed forA. pundulatus farauti.An attempt was made to determine the ages of the females captured at night and during the day by means of the criteria of ovary development, wing condition, presence of blood and of spermatozoa. The interpretation of these criteria was assisted by observations on bredA. pundulatus pundulatus.